1. Field of the Invention
The present invention relates to a lens processing management system, particularly, a lens processing management system for unitarily managing and controlling a plurality of types of processing machines included in a lens manufacture line and information in the line.
2. Related Background Art
Conventionally, so-called group management systems for unitarily managing and controlling various processing machines have been proposed. For example, systems for group management of injection molding machines used for plastic molding have been devised, which are disclosed in Japanese Patent No. 2543793, etc.
On the other hand, in the field of lens processing, as disclosed in Japanese Patent Application Laid-Open No. 06-315849, etc., in certain partial fields, systems have been used in which a processing system and a measuring system are connected with each other through a LAN (Local Area Network), and an operation program for a numerically-controlled polishing machine is automatically calculated in accordance with measurement values by the measuring system and then it is transferred to the processing machine side.
Besides, Japanese Patent Application Laid-Open No. 2000-176811 discloses an automatic lens processing “line” from the supply of a lens material to a polishing process or a centering process. In the field of lens processing, however, no group management system for unitarily managing and controlling many processing machines and information on many “lines”, as in the field of plastic molding, have been known.
As the reasons can be mentioned that: (1) there are types of processes to finish the shape of one lens as a product; (2) there are many items to be managed in each process; (3) there are many types of processing machines and many types of tools to be managed; etc. That is, in lens processing, after the material is supplied, the spherical portion of each face (front and back) is finished through processes called rough grinding, smoothing, and polishing, and further, processes such as centering and vapor deposition of an antireflection film are performed to complete an individual lens.
The flow from the supply of a lens material till completion of the lens is disclosed in detail also in the above Japanese Patent Application Laid-Open No. 2000-176811. In the processes to finish each spherical portion (rough grinding to polishing), in order that each of the curvature of the spherical portion, the spherical accuracy (astigmatism and CONTR MP), the appearance quality (surface roughness, the presence of scarring, etc.), the thickness, etc., may achieve an aimed quality level when the polishing process has ended, quality management works such as quality checking in each process (rough grinding, smoothing, and polishing) and changing set conditions of each processing machine are very important factors. Incidentally, “astigmatism” is a technical term concerning an error in shape of a sphere (spherical accuracy), which means an axially asymmetrical component of an erroneous shape deviated from a true sphere (this term is used only in case that the shape can be judged by an interference fringe, i.e., in part of the polishing or smoothing process). Also, “CONTR MP” is a technical term concerning an error in shape of a sphere (spherical accuracy), which means an axially symmetrical component of an erroneous shape deviated from a true sphere (this error is judged by an interference fringe, like in case of the above “astigmatism”). For the above-described reason, even if processes such as the supply of the material, conveyance, and the attachment/detachment of the lens material to/from each processing machine were automated, the work of the quality management in each process had to be done manually. For this reason, the number of workers could not easily be decreased.
FIG. 15 illustrates a table showing quality items to be managed in each process for lens manufacture.
As illustrated in FIG. 15, quality items to be managed differ from process to process. Besides, many items must be managed in one process. In order that these quality items may fulfill the respective standard values, an operator who are managing the lens manufacture line performs periodic measurements and further, in accordance with the measurement values, performs the adjustment of setting conditions of each processing machine and a revision of tools. For the quality measurements performed by the operator, measurements on micrometer level are required and the greatest care must be taken in adjusting and treating the measuring machines, besides skillful techniques are required. Additionally, as the processing machine used in each process, in accordance with the shape of the lens to be processed (curvature, aperture angle, convexoconcave “unevenness in height”, diameter, etc.), proper one of various types of processing machines is used. In this case, since the adjustment methods vary from processing machine to processing machine, skillful techniques, a great deal of knowledge, and many experiences are required for this work.
Besides, most of tools to be used in each process are exclusive to the respective lens shapes, and so, in the smoothing and polishing processes, a pre-revision work for tool shape by an expert, called bowl fitting, greatly influences the lens quality.
Further, although periodical checks (measurements) for each quality item being managed are carried out, there is a difficulty that the timings for carrying out the quality checks differ from item to item.
As described above, in the field of lens processing, because of the numerousness of items to be managed in each process and the presence of measurement and adjustment works that require skillfulness, such group management techniques as disclosed in the field of plastic molding could not be applied.
As described above, in the field of lens processing, manufacturers have not completely left production systems of long standing that rely upon experts, and a recent rise of labor cost is gradually weakening their competitive powers in cost. For ridding themselves of this situation, the number of manufactured lenses per worker must be increased as much as possible to decrease the labor cost. For this purpose, it is required to construct a production system in which lenses can be processed without relying upon experts and to decrease loss of time in manufacture, such as setup, adjustment, and idle walking, as much as possible.